Simple cleanup on Spark's Scala code while testing core and yarn modules:
-) Remove some of unused imports as I found them
-) Remove ";" in the imports statements
-) Remove () at the end of method call like size that does not have size effect.
Merge pull request #178 from hsaputra/simplecleanupcode

Simple cleanup on Spark's Scala code

Simple cleanup on Spark's Scala code while testing some modules:
-) Remove some of unused imports as I found them
-) Remove ";" in the imports statements
-) Remove () at the end of method calls like size that does not have size effect.
Slightly enhanced PrimitiveVector:
1. Added trim() method
2. Added size method.
3. Renamed getUnderlyingArray to array.
4. Minor documentation update.
Return the vector itself for trim and resize method in PrimitiveVector.
Add PrimitiveVectorSuite and fix bug in resize()
Merge pull request #3 from aarondav/pv-test

Add PrimitiveVectorSuite and fix bug in resize()
Merge pull request #182 from rxin/vector

Slightly enhanced PrimitiveVector:

1. Added trim() method
2. Added size method.
3. Renamed getUnderlyingArray to array.
4. Minor documentation update.